The present invention relates to a technology for distributing multimedia data (which is also called the “contents data”) as electronic data to a purchaser of the multimedia data and, more particularly, to a technology for managing the multimedia data by embedding the information to manage the distribution route or the like of the multimedia data in the multimedia data by using the electronic watermarking technique.
In recent years, from a viewpoint of protecting the copyright for digitized multimedia data such as image data or voice data, the electronic watermark technology has been highlighted. This electronic watermark technology is a technique for embedding a predetermined information in multimedia data in accordance with a predetermined rule so that the predetermined information cannot be extracted from the multimedia data without using at least the predetermined rule. The predetermined information to be embedded in the multimedia data can be exemplified, in a case In a case where the contents are books, by utilizing the international standard numbers called the “ISBN (International Standard Book Number)” indicating the nationality, the publisher and the book titletitle in ten digits and, in a case In a case where the contents are musics, by utilizing the international standard codes called the “ISRC (International Standard Recording Code)” specifying the voice source.
Here, in recent years, it has been tried to distribute the multimedia data such as the image data or the voice data through a network such as the online system or the Internet. In a case In a case where the multimedia data are to be distributed through the network, it is important how to manage the distribution route of the multimedia data.
In a case where the multimedia data are to be sold by recording them in recording media such as a DVD, a CD-ROM or an FD, the individual distribution routes of the recording media can be managed by printing the serial numbers on the labels of the recording media in addition to the aforementioned ISBN and ISRC or by embedding the multimedia data themselves as the watermark information in the multimedia data themselves, so that the individual shops may manage the serial numbers of the recording media sold by themselves.
The distribution route managing method described above is premised by a fact that the number of recording media having been shipped to the market is known in advance.
In a case where the multimedia data are to be distributed through the network, on the contrary, the individual shops (e.g., distributing persons or companies) copy the multimedia data (or masters) to be purchased, which is held in the shops, when the multimedia data are to be distributed to the purchasers, and then distribute the copies to the purchasers through the network. In other words, the multimedia data are produced at the time of a request for purchasing them, so that the number of multimedia data to be shipped to the market cannot be known in advance.
In this sales mode, too, there has been desired a technology for managing the distribution route.